This application is based on and hereby claims priority to Japanese Application No. 2000-69606 filed on Mar. 14, 2000 in Japan, the contents of which are hereby incorporated by reference.
1. Field of the Invention
The present invention relates to equipment used for exchanging sensible heat, latent heat, or total heat energy between plural fluid streams.
2. Description of the Related Art
Heat exchangers are classified into roughly two categories; those in which the heat exchange medium does not move and those in which the heat exchange medium moves.
Heat exchangers that move the heat exchange medium generally exchange heat efficiently. However, they also have a complicated structure.
One example of a movable heat exchange medium is a honeycomb rotor, in which the rotor has small passages that resemble the nest of a bee. The honeycomb rotor is cylinder shaped. For this device, gas is passed through the honeycomb rotor as it rotates.
A heat exchanger using a honeycomb rotor will exchange sensible heat if the sheet material forming the honeycomb rotor does not have water adsorption properties. The same heat exchanger will serve as a latent heat or total heat exchanger, if the sheet material carries a moisture adsorbing agent thereon.
Heat exchangers that use a honeycomb rotor have the problem that gas remains in the small channels of the honeycomb rotor as it rotates between the hot and cold fluids. Some of the retained gas from one zone is the released in the other zone. Therefore, when performing heat exchange between different kinds of gases, there may be some mixing of the different kinds of gases.
When this problem is serious, a purge zone may be provided to drive out gas remaining in the small channels of the honeycomb rotor. Within the purge zone a fluid is passed through the honeycomb rotor to expel gas retained within the rotor.
However, there is a problem associated with processing the gas which comes out of the purge zone. The gas which comes out of the purge zone is a mixture of gases. Previously, there were two ways of treating the purged and mixed gas: by discharging it into the atmosphere or by returning the gas mixture to one of the gas streams, which gas stream can tolerate having another gas mixed therein.
Both solutions have problems. In the former, the method of treatment is often not available because the purged and mixed gas may not be acceptable for discharge into the atmosphere for health or environmental reasons. Furthermore, even if discharge is acceptable, it detracts from heat exchange efficiency. The latter method of treatment is often not ideal because often neither of the gas streams can tolerate having another gas mixed therein.
In response to the difficulties discussed above and problems encountered in the prior art, a new heat exchanger, method of heat exchange and vehicle drive device having heat exchanger have been invented. The heat exchanger includes a honeycomb rotor, a drive unit and a gas movement device. The honeycomb rotor has at least two heat exchange passages and at least two purge zones provided respectively between the at least two heat exchange passages. The drive unit rotates the honeycomb rotor. The gas movement device circulates a gas through the at least two purge zones.
The gas movement device may include a blower, and the drive unit may include a motor. In this case rotation of the blower can be synchronized with rotation of the motor. Specifically, rotation of the blower can be synchronized with rotation of the motor by supplying the blower and the motor with power from a common inverter.
An adsorbent, such as a zeolite or a silica gel may be carried on the honeycomb rotor. The honeycomb rotor may be formed of alternately laminated flat and corrugated sheets.
The vehicle drive device having a heat exchanger includes a power source, a honeycomb rotor, a drive unit and a gas movement device. The power source emits exhaust gas and employs a fuel battery having an air intake. The honeycomb rotor has at least two heat exchange passages, with the exhaust gas being directed through a first of the heat exchange passages and inlet air being directed though a second of the heat exchange passages prior to being sent to the air intake of the fuel battery. The honeycomb rotor also has at least two purge zones provided respectively between the at least two heat exchange passages. The drive unit rotates the honeycomb rotor. The gas movement device circulates a gas through the at least two purge zones.